Transmitting apparatus for wireless telegraphy.



G. MARGONI.

' TRANSMITTING APPARATUS FOR WIRELESS TELEGRAPHY. APPLICATION FILED JULY15, 1910,

, 997,308; Patented July 11,1911.

UNITED STATES PATENT OFFICE.

GUGLIELMO 'MARCONI, OF LONDON, ENGLAND, ASSIGNOR TO MARCONI WIRELESS ITELEGRAPH COMPANY OF AMERICA. OF NEW YORK, N. Y., 'A CORPORATION OF NEWJERSEY.

Specification of Letters Patent.

Patented July 11, 1911.

Application filed July 15, 1910. Serial No. 572,070.

To all whom 'it may concern:

Be it known that I, (xUeLmLMo MARooNI, LL. D., 1'). So, a subject of theKing of Italy, residing at \Vatergate House, Ade phi, London, England,have invented new and useful Improvements in Transmitting Apparatus forWireless Telegraphy, of which the following is a specification.

It has before been proposed to employ a transmitter in which the gapbetween two terminals of the oscillation circuit is more or less bridgedat regular intervals by means of bridging pieces in very rapid movement,these bridging pieces preferably consisting of studs fixed to a rapidlyrevolving disk. N ow it is found that it is very advantageous to obtaina greater number of discharges per second, and this can be done byincreasing the number of pairs of studs on the disk and the speed ofrotationof the disk. A difliculty however arises, for at the occurrenceof each discharge the condenser is shunted and when the discharge stopsthe shunt is broken and the condenser is charged by the generator withoscillations, the time period of which is dependent upon the wholeinductance of the circuit including that of-the alternator ortransformer if an alternating current generator be employed or of thedynamo armature if a continuous current generator be employed. But toreduce this time period to the very small fraction of a second which isnow found to be desirable it is necessary such inductance should be lessthan that of any known dynamo.

According to this invention therefore and in order to reduce theinductance of the charging circuit the dynamo is replaced by a batteryof low resistance having a sufficiently large number'of cells. connectedin series to give the necessary E. M. F. In circuit with the battery isplaced an inductance of suitable value to satisfythe above statedconditions. Preferably a secondary battery is employed which is keptconstantly charged by a continuous current dynamo. The diagram showssuch a transmitter, a being the battery connected through a sending key6 and inductances c to a condenser 03 which is connected to slowlyrotating disks 0 one of the connections including. the

primary of the inductive coupling f to the aerial g.

h is a disk which can be very rapidly rotated so that the studs 9 uponit bridge at very short intervals'the gap between the disks e.

What I claim is 1. In a transmitter for wireless telegraphy, thecombination in an oscillation circuit of a battery of low resistance,moving terminals therefor, arranged so that a gap is left between them,bridging pieces adapted to bridge such gap, and means for rapidly movingthe bridging pieces past the gap.

2. In a transmitter for wireless telegraphy, the combination in anoscillation circuit of a battery of low resistance, moving terminalstherefor, arranged so that a gap is left between them, an insulateddisk, studs located at regular intervals on said disk and adapted tobridge the gap, and means for rapidly rotating the disk.

3. In a transmitter for wireless telegraphy, the combination of abattery of low resistance, a condenser adapted to be charged thereby, apair of terminals connected to the condenser, an inductance in serieswith the condenser and terminals, means for rotating the terminals, aninsulated disk, studs located at regular intervals thereupon and adaptedto bridge the gap between the terminals, and means for rapidly rotatingthe disk.

4. In a transmitter for wireless telegraphy, the combination of abattery of low resistance, a condenser adapted to be charged thereby, apair of terminals connected to the condenser, an inductance in serieswith the condenser and terminals, means for rotating the terminals andmeans operating at intervals bearing an integral ratio to the electricaltime period of the circuit containing the condenser and battery forbridging the gap between the terminals.

5. In a transmitter for wireless telegraphy, the combination of abattery of low resistance, a condenser adapted to be charged thereby, apair of terminals connected to the condenser, an inductance in serieswith the condenser and terminals,

\ means for rotating the terminals, an insulated disk having studslocated at regular intervals upon it and adapted to bridge the gapbetween the terminals, and means for 5 rapidly rotating the disk so asto bridge the gap between the terminals at intervals bearing an integralratio to the electrical GUGLIELMO MAROONI.

Witnesses E. P. TURNBULL, J ST. VINCENT PLETTB.

